1. Field of the Invention
The present invention relates generally to a method and apparatus for creating still picture management data on a rewritable storage media, and more particularly, but not by way of limitation, to a method and apparatus capable of reducing the amount of navigation information and index information needed to record still pictures on a rewritable storage media.
2. Brief Description of the Related Art
Currently, a great number of optical disks are being used in various fields. With the advent of the DVD (Digital Versatile Disc), it is expected that more and more optical disks will come into use. Optical disks currently include read-only disks such as the CD-ROM and DVD-ROM and record-once disks such as the CD-R and DVD-R. In addition, specifications for rewritable optical disks such as the CD-RW, DVD-RAM, and so forth are now under discussion.
Since rewritable optical disks like the DVD-RAM have very large capacity, they can store a good many moving/still images. When moving/still images are recorded on a rewritable storage media, information for search and retrieval of the images is created and recorded in a navigation information file on the storage media.
The structure of the navigation information file is shown in FIG. 1, wherein the VOB (Video Object) information field and cell information field are created and inserted in the navigation information file, each time a moving or still image is recorded on the storage media. When reproducing images, the navigation information file is loaded into a memory, and a requested moving or still image is searched for and reproduced from the storage media based on the navigation information.
Since still pictures are much smaller in size than moving pictures, a large number of still pictures can be recorded in a storage mediaxe2x80x94for example, a 4.7 GB storage media can store more than 60 thousand still pictures. Therefore, when a high-capacity storage media is filled with only still pictures, the amount of necessary navigation information increases relative to the stored still images. When a still picture or audio data linked to the still picture is recorded, the two information fields in FIG. 1 (i.e., VOB information and cell information (CI) fields) take up 84 bytes (e.g., S_VOB (36 bytes)+Cell (2xc3x9724 bytes)) including the reserved area. In the above example, therefore, the size of the two information fields needed to store 60 thousand still pictures is 5040 KB (84xc3x9760000). FIG. 2 shows the relation between VOB information and cell information created when still pictures are recorded.
As a result, even when limited to storage of still pictures, the size of the navigation information file in a storage media exceeds 5 MB. As mentioned above, the navigation information file needs to be loaded into a memory and searched to locate and retrieve a requested still picture from the media; hence a large memory is required merely to store the navigation information temporarily. If the size of the memory is limited, for example less than 512 Kbytes, the number of still pictures to be recorded should also be limited despite the large capacity of the storage media, which is a major problem of the conventional still picture management method.
The present invention is directed to a system that substantially obviates one or more of the problems experienced due to the above and other limitations and disadvantages of the related art.
It is an object of the present invention to provide a method and apparatus for creating and recording still picture management data in a rewritable storage media, which remarkably reduces the size of necessary still picture management data by sharing navigation information of a plurality of still pictures.
Other and further objects, features and advantages of the present invention will be set forth in the description that follows, and in part will become apparent from the detailed description, or may be learned by practice of the invention.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, the present invention includes a method for recording pictures such as still pictures on a rewritable storage media including recording obtained still pictures in sequence; examining conditions for grouping the recorded still pictures into single video object (VOB); and creating and recording navigation information for the still pictures grouped according to the examination result. Furthermore, the method linked to the still pictures on a rewritable storage media includes recording obtained still pictures and/or audio signals which will be reproduced together with correspondent still pictures; examining conditions of still pictures or audio signals for grouping the recorded still pictures and/or audio signals into single data object which may consist of only audio data instead of only video or mixed data; and creating and recording of navigation information for the still pictures and/or audio signals grouped according to the examination result.
In addition; the present invention includes a rewritable storage device, the contents of the rewritable storage device including several or recorded pictures, one or more groups of the recorded pictures having one or more common attributes; and navigation information used to identify the groups of recorded-pictures based on the common attributes shared by the pictures within the groups. The recorded pictures are generally still pictures and the number of pictures in a group is generally limited to a present maximum number. The navigation information includes information on a start address of a corresponding group identified by the navigation information and information on sizes of the still pictures within the group identified by the navigation information. The information on the sizes of the still pictures within the group is recorded sequentially according to a recording order of the still pictures within the group, the information on the sizes identifying the size of more than one still picture within the group.
In the present invention, conditions for grouping the recorded still pictures and audio signals linked to the still pictures into VOBs include attributes of the still pictures and audio signals and the maximum number of still pictures which a VOB can contain.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. Thus, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of example only. Various changes and modifications that are within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. In fact, other objects, features and characteristics of the present invention; methods, operation, and functions of the related elements of the structure; combinations of parts; and economies of manufacture will surely become apparent from the following detailed description of the preferred embodiments and accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in various figures.